Technical Abstract:
The administration of nonpathogenic microflora in neonatal poultry has been employed to reduce or eliminate the colonization of enteric pathogens. This concept, also called competitive exclusion (CE), although effective against Salmonella, has not consistently worked against Campylobacter. Most CE cultures are developed by randomly collecting enteric bacteria without any preselection criteria for bacteria. It may be possible to enhance the efficacy of a CE against Campylobacter by preselecting enteric microflora with the ability to inhibit Campylobacter, in vitro. With this goal, an assay was developed to test individual isolates with the ability to reduce or eliminate Campylobacter growth, in vitro. Individual isolates were obtained from cecal material of both juvenile and adult poultry. Isolates were serially diluted (1,000, 10,000 and 100,000 CFU/well) and added to 96 well polystyrene plates containing 1x 1,000 CFU C. jejuni or C. coli/well. Plates were incubated at 42 C in a microaerophilic environment for 22 to 24 hours. Following incubation, a 1 microliter loop from each well was streaked onto Campy-Cefex and incubated at 42 C in a microaerophilic environment for 24-48 hours. Approximately 30 isolates were identified with the ability to inhibit C. jejuni or C. coli growth in vitro. Preliminary studies using combinations of these isolates in neonatal poults demonstrated some efficacy against Campylobacter colonization. This research demonstrates in vitro efficacy of isolates against Campylobacter, however additional research will be required to identify combinations of isolates with the ability to consistently inhibit Campylobacter colonization in vivo. Funded in part by the USDA Food Safety Consortium.